Dr. Luis Eduardo Bravo is the Principal Investigator and supervises all activities in Colombia. He is based in Cali and travels often to Pasto. His administrative assistant in Cali is Mr. Tito Collazos who has been the administrator for all the life of the Program Project. His data manager assistant is Mrs. Stella Garcia, who has been in charge of those activities for approximately 10 years and has become extraordinarily skilled and efficient. The data generated in Pasto are entered and edited by Mrs. Alicia Rosero, who also has been conducting these activities very efficiently for years. Mrs. Rosero transmits the data via Internet to New Orleans and New Jersey for Dr. Mera. The field team in Narino is under the direction of Dr. J. Luis Realpe, who is also the gastroenterologist and endoscopist in charge. He is based at Hospital Departmental. He is assisted by Dr. Alvaro Bedoya, endoscopist based at Hospital Infantil, in charge of children's clinical studies. The field team is based at Universidad de Narino (Pasto) under the direction of Nurse Maria Clara Yepez. She has trained outstanding assistants (nurses-social workers). Mrs. Cristina Campo supervises the clinical nursing and data managing team in Narino. Dr. Juan Carlos Bravo is assistant pathologist for gastric biopsies interpretation. The biopsies are fixed and embedded in paraffin in Colombia. A first section is stained and used for diagnostic uses communicated to the clinician. The paraffin blocks are then transported to New Orleans for further processing, immunohistochemistry and other special procedures.